Dust distributor



Feb. 6, 1968 w. E. COOK ETAL 3,367,541

DUST DISTRIBUTOR Filed April 6, 1966 M/l/E/VTORS WALTER E. 600/( andCHARLES HARPER Allornay United States Patent Ofiice 3,367,541 DUSTDISTRIBUTOR Walter E. Cook, Uniontown, and Charles Harper, Monongahela,Pa., assignors to United States Steel Corporation, a corporation ofDelaware Filed Apr. 6, 1966, Ser. No. 540,683 3 Claims. (Cl. 222-193)ABSTRACT OF THE DISCLOSURE An apparatus for distributing rock dust in acoal mine to overcome fire and explosion hazards. Includes a portablehopper, a porous diaphragm near the bottom of the hopper, and a plenumchamber below the diaphragm. Compressed air is forced into the plenumchamber, and fluidizes dust in the hopper. The dust discharges onto ashelf from which it is blown into the surrounding atmos phere.

This invention relates to an improved apparatus for distributing dust,for example rock dust in a coal mine to overcome fire and explosionhazards.

Float coal dust in return air courses of a coal mine constitutes a fireand explosion hazard. It is known that the hazard can be overcome bydistributing rock dust (usually limestone) in air which carries coaldust. The rock dust neturalizes the coal dust and forms an inertmixture.

An object of our invention is to provide an improved dust distributorwhich continuously discharges small quantities of dust suspended in air,whereby the resulting dust suspension can be introduced to a return aircourse.

A further object is to provide a distributor of the foregoing type whichis of simple construction and easy to operate, yet effectivelydistributes dust on a continuous basis. 7

In the drawings:

FIGURE 1 is a side elevational view with parts broken away of our dustdistributor;

FIGURE 2 is a rear elevational view with parts broken away from theright of FIGURE 1; and

FIGURE 3 is a horizontal section on line IIIIII of FIGURE 1.

Our dust distributor includes a hopper 10, which has an internal ledge12 near the bottom. We fasten a porous diaphragm 13 across the hopper onledge 12. The hopper is open at the top and conveniently is ofrectangular cross section and formed of metal or wood. Conveniently weform the diaphragm of fabric, such as canvas. The sides of the hopperhave handles 14 for transporting the distributor. We introduce a supplyof rock dust R to the space within the hopper above the diaphragm.Preferably the hopper has a capacity of about 200 pounds of rock dust.The space between the bottom wall of the hopper and the diaphragmconstitutes a plenum chamber 15.

We attach a pipe T 16 to the back wall of hopper 10. To one arm of the Twe join a hose coupling 17 through suitable connectors, as we illustratein FIGURE 2. We connect a hose 18 to the coupling 17. The hose leads toa compressed air supply. To the lower end of the T we conmeet a verticalpipe 19 which leads to the plenum chamber 15. Pipe 19 contains a valve20. Air introduced to the plenum chamber via pipe 19 flows upwardlythrough the porous diaphragm 13 and fluidizes the bed of dust particlesR. The front wall of the hopper carries a downwardly curved dischargepipe 21, which terminates in a Patented Feb. 6, 1968 flexible hoseportion 22. The front wall of the hopper carries a shelf 23 whichextends beneath the discharge pipe 21. The shelf has an upwardly slopinglip 24 at its outer edge. The lower end of hose 22 lies immediatelyabove the upper surface of the shelf. The discharge pipe 21 and hose 22carry a suspension of rock dust particles in air to the shelf.

The plenum chamber 15 contains a pipe 25 which extends from its backwall to its front wall. To the second arm of the T 16 we join adownwardly extending tube 26 through suitable connectors, as Weillustrate in FIG- URE 2. Tube 26 contains a stopcock 27. The tube bendsand extends horizontally through pipe 25 and terminates in an air nozzle28. This nozzle lies immediately behind the outlet end of hose 22 aboveshelf 23. Air emitted from the nozzle blows the rock dust suspensionfrom the hose over the lip 24 and into the surrounding atmosphere. Therock dust suspension thus discharges continuously and effectively mixeswith the coal dust carried by the atmosphere.

From the foregoing description it is seen that our invention affords asimple and effective apparatus for distributing rock dust into returnair courses of a coal mine. The apparatus is readily portable for usewhere needed, and is easily controlled by adjusting the valve 20 andstopcock 27.

While we have shown and described only a single embodiment of ourinvention, it is apparent that modifica tions may arise. Therefore, wedo not wish to be limited to the disclosure set forth but only by thescope of the appended claims.

We claim:

1. An apparatus for distributing dust comprising a hopper, a porousdiaphragm extending across said hopper and adapted to support a bed ofdust, said diaphragm be ing spaced above the bottom wall of the hopperto form a plenum chamber, means connected to said chamber forintroducing compressed air thereto and thence through said diaphragm tofluidize the dust, a discharge pipe connected to said hopper above saiddiaphragm and terminating in a downwardly extending hose, a shelfcarried by said hopper beneath said pipe, the lower end of said hoselying immediately above the upper surface of said shelf, an air nozzlesupported by said hopper adjacent the lower end of said hose, and meansfor introducing compressed air to said nozzle for blowing a suspensionof dust from said shelf.

2. An apparatus as defined in claim 1 in which the means for introducingcompressed air to said chamber and to said nozzle includes a pipe Tfixed to a Wall of said hopper, a hose coupling joined to one arm ofsaid T, a pipe connected to the lower end of said T and to said chamber,and a tube connected to the other arm of said T and to said nozzle.

3.'An apparatus as defined in claim 1 in which said shelf has anupwardly sloping lip at its edge over which the suspension is blown.

References Cited UNITED STATES PATENTS 2,441,700 5/1948 Hammell 239336 X2,758,564 8/1956 Randall 1l8309 2,919,160 l2/l959 Blackburn 30257928,374 7/1909 Ford et al. 222l93 (Other references on following page)UNITED STATES PATENTS Mack 222148 Feller 222195 Gorin 222195 Knutsen222195 McIlvaine 222195 Ashman 222193 Gmur et a1 222195 4 3,201,0008/1965 Hermanns 222195 3,254,766 6/1966 Anderson 222195 FOREIGN PATENTS181,505 11/1962 Sweden.

ROBERT B. REEVES, Primary Examiner.

RAPHAEL M. LUPO, Examiner.

